Advertisements
Advertisements
प्रश्न
How unit of power related to focal length of a lens?
Advertisements
उत्तर
Power is expressed as inverse of focal length, f (in metres).
`"Power (in Diopters) ="1/"Focal length (in metres)"`
APPEARS IN
संबंधित प्रश्न
What is meant by a power of a lens? Define its SI unit.
The lens mentioned in 6(b) above is of focal length 25cm. Calculate the power of the lens.
Name the physical quantity whose unit is dioptre.
Which has more power : a thick convex lens or a thin convex lens, made of the same glass? Give reason for your choice.
What is the power of a convex lens of focal length 0.5 m?
The power of a lens is + 1.0 D is :
Consider three converging lenses L1, L2 and L3 having identical geometrical construction. The index of refraction of L1 and L2 are \[\mu_1 \text{ and } \mu_2\] respectively. The upper half of the lens L3 has a refractive index \[\mu_1\] and the lower half has \[\mu_2\] following figure . A point object O is imaged at O1 by the lens L1 and at O2 by the lens L2placed in same position. If L3 is placed at the same place,
(a) there will be an image at O1
(b) there will be an image at O2.
(c) the only image will form somewhere between O1 and O2
(d) the only image will form away from O2.
How is accommodation produced?
Increase in the converging power of eye lens cause ‘hypermetropia'
Assertion and reasoning type
- Assertion: Myopia is due to the increase in the converging power of eye lens.
- Reason: Myopia can be corrected with the help of concave lens.
